How does one follow an Alexander McQueen wedding dress that has had the fashion world and twittersphere in paroxysms of joy?

The answer, according to the new Duchess of Cambridge, is with another Alexander McQueen evening dress in a similar mould. As the saying goes: if it ain't broke, don't fix it.

The evening dress, like the wedding dress, was designed by Alexander McQueen's protegee, Sarah Burton. The strapless, ivory silk gazar dress, with fitted strapless bodice and circle skirt, echoed the shape of the dress worn to the morning's ceremony.

However, the delicate lace top layer and sleeves, which added modesty and solemnity to the outfit at the Abbey, had vanished for the evening, replaced with a dazzling diamante waist detailing.

An angora cardigan, worn for decorum in front of the early evening television cameras, kept up appearances, but looked destined to be banished once Kate was safely away from prying paparazzi and back inside Buckingham Palace for the evening.

There, the newlyweds, together with 300 of their closest family and friends, attended a party hosted by the Prince of Wales. The Queen gave over her home to the celebration, having chosen to head off for a private weekend away.

The evening dress cemented a day of triumph for Burton. With many designers in the frame for the prestigious royal wedding commission, it had been suggested that at least two designers might be involved.

In the event, Sarah Burton claimed all three of the most prestigious commissions of the day: the day and evening gowns of the bride, and the ivory bridesmaid gown for Pippa Middleton, which had half the audience – and, it seemed on occasion, Prince Harry – gripped.

In an era when messaging is all, the synergy between Catherine's wedding and evening gowns was immaculate. The new duchess's evening gown looked to be a pared back version of her wedding dress, without the lace overlay.

The dress was an undone version of her Westminster Abbey outfit, but with the lace overlay replaced by a sparkling diamante cuff at the waist. Catherine's decision to forgo the opportunity for a second "wow" moment in her dress hints at a natural confidence.

A less sure woman would perhaps have split her bets, choosing a different designer or silhouette for her all-important evening appearance. That the new Duchess of Cambridge had the confidence to put all her eggs in one McQueen, late-50s basket says much about the royal family's newest recruit.

Her sister Pippa had changed from her bridesmaid dress into a long emerald green sleeveless dress with a jewelled embellishment on the front and a plunging neckline.